Yellowstone National Park is currently (as of summer of 2012) home to roughly 4,200 wild American bison. Compared to the tens of millions that used to roam free across this entire continent and from Alaska to northern Mexico, this number is very--well, sad. It is frequently and very mistakenly argued that 3,000 buffalo is too many, that this number exceeds the ecological carrying capacity of Yellowstone's habitat, thereby justifying the on-going buffalo slaughter under the Interagency Bison Management Plan. According to a recent study using scientific modeling, bison "have not reached a theoretical food-limited carrying capacity of 6,200 in Yellowstone National Park."

Under the guise of "disease risk management" and the Ineragency Bison Management Plan, Montana Dept. of Livestock inspectors and National Park Service rangers harrass and intercept bison off their winter range and spring calving grounds and capture bison in a slaughter program in patnership with Yellowstone Park. They have succeeded in destroying over 3,200 wild buffalo in the last decade. The bison are killed for stepping across arbitrary lines drawn in Montana, Idaho, and Wyoming. Montana and Yellowstone swear by the undocumented claim that grazing cattle are at risk of brucellosis--a disease introduced by exotic cattle to native elk and buffalo that had been "mothered by domestic bovine cows" before 1917. There has never been a documented case of a wild buffalo transmitting this disease to livestock.